There are no new Messis to carry on this era of Barcelona glory
There is always a time when a great football team is suddenly more an idea, a fading dream, than a living reality.
This is so even if some hard judges, including Roy Keane, are reluctant to assign Barcelona to such place in the history of the game they have illuminated so brilliantly for so long.
But then who can say that the evidence is not now building way beyond mere suspicion?
The case against them could not have been waged more damagingly this week when a superbly organised Juventus concluded their crushing 3-0 aggregate Champions League quarter-final victory at a disbelieving Nou Camp.
It was not so much a win as an undressing, an exposure, one so profound that for every banner waved defiantly by a Barca loyalist there must have been at least one bone-deep shudder over the prospect of Sunday's El Clasico at the Bernabeu fortress of Real Madrid.
Three points adrift of Real, having played one game more, Barcelona are peering at their fate from the wrong end of the gun barrel.
More rampage from Cristiano Ronaldo, perhaps a little of the kind of assistance provided by the referee in the cruel defeat of Bayern Munich on Wednesday night, and Real have the power to do historic damage to their fierce rivals. They can make Barca's season more than a cruel descent from the peak they enjoyed two springtimes ago with a stunning treble of Champions League, La Liga and the Copa del Rey. They can make it the breaking point of one of the game's greatest dynasties.
Keane for one shakes his head at such a prediction. Normally as pitiless in his judgement as he was in the tackle, he says that Barca may need no more than some reinventions from Lionel Messi and the re-appearance of the real Luis Suarez and Neymar Junior rather than the showy imposters shut down so imperiously by the Juve defence. Yet even Keane in a rare romantic mode, allows that Barca must make a replacement at least as crucial as the one for departing coach Luis Enrique.
They have a need for a new Andres Iniesta, as they have had for a Xavi Hernandez in the steady decline of the great Iniesta's ability to be the creative midfield soul of the team.
What Barca need most of all is a harder understanding that teams can shed greatness as quickly as they sometimes acquire it. It is a quality forfeited for a variety of reasons, a change in team chemistry, in the promptings of a Pep Guardiola or Enrique, the failing ambition of the most vital players, but, most importantly of all, a dwindling of the belief that even the most accomplished of teams need regular re-seeding.
At the peak of Guardiola's success at the Nou Camp, with three straight La Liga titles and two Champions League wins in three years, he walked away, pleading the need to refresh himself, to take time for a breath or two beyond the inhalation of his team's glory. It was a decision which bemused the old pro Alex Ferguson, whom Guardiola had just beaten for his second European crown, because it defied one of his core beliefs. This was that you can spend your entire career pursuing the goal of a perfect team and that if you ever have it, you should guard it for yourself as the most brilliant jewel.
"The reality," said Ferguson with a shake of his head, "is that it may never come again."
Perhaps Barcelona have become victims of the Guardiola syndrome. Perhaps they assumed down the years of success, the weight of acclaim, that greatness was something to be renewed when the need became unassailably real, not when it presented itself in an occasionally off-colour Iniesta or a dwindling Xavi.
Barcelona became huge on the back of Messi's genius and Guardiola's insight into the range of the player's phenomenal gifts. And there was the thrust to greatness. But then where does it lay now? Messi will be 30 next season and there were times this week when he seemed to be counting all the years in which he had been required to make interventions that changed not only matches but entire seasons.
There are no new Messis, fuelled by other-worldly ability and built up by growth hormones, dazzling the playing fields of La Masia, once the El Dorado of youth development. Nor is there an Iniesta or a Xavi filled with precocious authority in shaping a midfield, as was evident in Iniesta's over-burdened challenge of breaking the chains of Juventus defence.
The task of maintaining Barcelona's aura has, despite his first season of brilliant achievement, plainly wearied Enrique. Having seen his side fall so short of the miracle that overcame a 4-0 deficit to Paris Saint-Germain in the round of 16, Enrique looked, for the moment at least, as though he had aged a decade.
Keane's theory is that a proper replacement for Iniesta, wherever he lurks thus far unannounced, and the swift restoration to full working order of Suarez and Neymar, should at least push back Barca's day of accountability. But does this really address the growing sense that Barca may have been too negligent in the matter of protecting their own glory?
How zealously are they responding to the departure of Enrique? Have they any clue as to the identity of the next Iniesta, the new man of La Mancha who arrived in Barcelona as a boy and quickly became one of the main men in an epoch which, whatever life it has left, will never be forgotten?
Such questions will no doubt survive all the possibilities of the Bernabeu tomorrow night. They will continue to ask the most pertinent questions about how best to maintain the rhythms and the vision of a team capable of lighting up the football world.
How well Barcelona did that for so long is not part of the debate. If anyone doubts this, they could do worse than briefly consult Roy Keane.
- Real Madrid v Barcelona, Sky Sports 1, 7.45pm